Book Image

ARM® Cortex® M4 Cookbook

By : Mark Fisher, Dr. Mark Fisher
Book Image

ARM® Cortex® M4 Cookbook

By: Mark Fisher, Dr. Mark Fisher

Overview of this book

Embedded microcontrollers are at the core of many everyday electronic devices. Electronic automotive systems rely on these devices for engine management, anti-lock brakes, in car entertainment, automatic transmission, active suspension, satellite navigation, etc. The so-called internet of things drives the market for such technology, so much so that embedded cores now represent 90% of all processor’s sold. The ARM Cortex-M4 is one of the most powerful microcontrollers on the market and includes a floating point unit (FPU) which enables it to address applications. The ARM Cortex-M4 Microcontroller Cookbook provides a practical introduction to programming an embedded microcontroller architecture. This book attempts to address this through a series of recipes that develop embedded applications targeting the ARM-Cortex M4 device family. The recipes in this book have all been tested using the Keil MCBSTM32F400 board. This board includes a small graphic LCD touchscreen (320x240 pixels) that can be used to create a variety of 2D gaming applications. These motivate a younger audience and are used throughout the book to illustrate particular hardware peripherals and software concepts. C language is used predominantly throughout but one chapter is devoted to recipes involving assembly language. Programs are mostly written using ARM’s free microcontroller development kit (MDK) but for those looking for open source development environments the book also shows how to configure the ARM-GNU toolchain. Some of the recipes described in the book are the basis for laboratories and assignments undertaken by undergraduates.
Table of Contents (16 chapters)
ARM Cortex M4 Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Writing a C program to blink each LED in turn


This recipe extends the helloBlinky_c2v0 recipe introduced in the previous section, and includes a few more C programming statements. We'll call our new recipe helloBlinky_c2v1. uVision5's IDE features a so-called folding editor that allows blocks of code and comments to be hidden or expanded. This is quite useful for hiding complexity, allowing us to focus on the important details.

Getting ready…

First, we'll draw a flowchart describing what our program will do. Don't worry about the details at this stage, we just need to describe the behavior. A flowchart describing helloBlinky_c2v1 is shown as follows:

Our program will need to change the value of a number stored in memory that determines the LED that is illuminated. Numbers coded in this way are called variables. The name of the variable is chosen by the programmer (usually programmers try to pick meaningful names); in this case, it's referred to by the identifier num. Since there are only eight...